Publication of Cost-of-Illness Studies: Does Methodological Complexity Matter?

The economic burden of influenza among adults aged 18 to 64: A systematic literature review

While the economic burden of influenza infection is well described among adults aged 65 and older, less is known about younger adults. A systematic literature review was conducted to describe the economic burden of seasonal influenza in adults aged 18 to 64 years, to identify the main determinants of direct and indirect costs, and to highlight any gaps in the existing published evidence. MEDLINE and Embase were searched from 2007 to February 7, 2020, for studies reporting primary influenza-related cost data (direct or indirect) or absenteeism data. Of the 2613 publications screened, 51 studies were included in this review. Half of them were conducted in the United States, and 71% of them described patients with influenza-like illness rather than laboratory-confirmed disease. Only 12 studies reported cost data specifically for at-risk populations. Extracted data highlighted that within the 18- to 64-year-old group, up to 88% of the economic burden of influenza was attributable to indirect costs, and up to 75% of overall direct costs were attributable to hospitalizations. Furthermore, within the 18- to 64-year-old group, influenza-related costs increased with age and underlying medical conditions. The reported cost of influenza-related hospitalizations was found to be up to 2.5 times higher among at-risk populations compared with not-at-risk populations. This review documents the considerable economic impact of influenza among adults aged 18 to 64. In this age group, most of the influenza costs are indirect, which are generally not recognized by decision makers. Future studies should focus on at-risk subgroups, lab-confirmed cases, and European countries.

Real World Cost-of-Illness Evidence in Hepatitis C Virus: A systematic review

BACKGROUND

The introduction of direct-acting antivirals (DAAs) represents a potential clinical cure for hepatitis C virus (HCV) infection. Identification of costs associated with different stages of untreated disease through cost-of-illness (COI) evaluation helps inform policy decisions and cost-effectiveness analyses (CEAs). This study's objective was to review published real-world costs for patients with HCV to estimate the COI across different stages of disease progression.

METHODS

A literature search of EMBASE, Scopus, and PubMed from January 1, 2010 to August 31, 2019 was conducted to identify real-world evidence related to HCV. Data extraction included citation details, population, study type, costing method used, currency and inflation adjustments, and disease-specific costs. Standardized costing method categories (sum all medical, sum diagnosis specific, matching, regression, other incremental, and other total) were assigned. The risk of bias was assessed at the outcome level for influence on costs attributable to HCV.

RESULTS

The search strategy identified 278 studies, with 31 included in the final review after inclusion and exclusion criteria were applied. Retrospective cohorts (77%) and cross-sectional analyses (16%) were most frequently encountered. Sum Diagnosis Specific was the most common costing method (39%), followed by Regression (32%). Of the 31 studies analyzed, 35% included costs that would be included in a societal model. Costs were identified for various stages and complications related to HCV disease progression. Several studies included were determined to have a high (48%) or moderate risk (42%) of bias related to COI estimates.

CONCLUSION

Cost estimates for formal, informal, and non-health care services were identified in this review, but several challenges still exist in fully quantifying HCV burden. Future modeling studies including cost inputs should critically evaluate the risk of bias based on costing methods and data sources.

Clinical and economic outcomes evaluated in Lyme disease: a systematic review

BACKGROUND

The financial implications of Lyme disease (LD) can vary widely for both the health system and the individual patients experiencing the disease. The aim of this review was to summarize published data on clinical and economic outcomes associated with LD.

METHODS

A literature review was conducted to identify all studies of LD that incorporate both clinical outcomes and costs. Included studies were described and categorized based on costs consistent with best practices used in economic evaluation.

RESULTS

The most frequent costs identified focused on formal health costs and productivity losses were the most common costs identified outside of the health system. Travel and informal care costs were less frequently reported. Clinical and economic outcomes of LD are primarily studied through economic models or observational analyses and focus on formal health care.

CONCLUSIONS

This review provides and overview of existing evidence and recommendations for future economic analyses in LD.

Medical Care Costs Associated with Genital Warts for Commercially Insured US Patients

INTRODUCTION

Genital warts are caused by infection with human papillomavirus (HPV) and are associated with significant morbidity. Primary prevention of genital warts is possible through HPV vaccination, but vaccination rates remain low in the USA. When deciding to implement HPV vaccination programs, public health officials and policy makers rely on cost-effectiveness studies that accurately reflect costs associated with morbidity and mortality. However, previous information on the cost of treating genital warts was outdated.

OBJECTIVES

We estimated the mean direct medical care costs associated with genital warts in the USA.

METHODS

This was a retrospective case-control study of patients diagnosed with genital warts and matched controls. We used commercial healthcare claims data from 2011 through 2014 to estimate total 1- and 2-year costs from date of diagnosis. We used a generalized linear model to identify factors associated with monthly costs.

RESULTS

We identified 34,686 eligible cases of genital warts during the period 2011-2014. The first 2-year mean direct medical cost differences between cases and controls were US$6737 for the USA. Costs were significantly higher in the first 3 months following diagnosis and were higher among older individuals, women, those with co-morbidities or psychiatric illnesses, and those located in the south and southwest USA.

CONCLUSIONS

The mean direct cost of treating genital warts is approximately US$6700 in the first 2 years after diagnosis in the USA. These data can assist policy makers in decisions with respect to allocation of resources to implement HPV vaccine programs.

Engaging hepatitis C infected patients in cost-effectiveness analyses: A literature review

Cost-effectiveness analyses (CEAs) of hepatitis C virus (HCV) treatment strategies have become common, but few appear to include patient engagement or the patient perspective. The objectives of the current study were to (1) identify published HCV CEA studies that include patient input and (2) derive insights on patient-informed variable and outcome selection to build a framework for future economic analyses of HCV. A literature search was conducted using SCOPUS, EMBASE, and PubMed from January 1, 2012 to May 28, 2017. Terms sought included a combination of "incremental cost-effectiveness ratio" OR "economic evaluation" OR "cost effectiveness analysis" OR "cost utility analysis" OR "budget impact analysis" OR "cost benefit analysis" AND "hepatitis C". A total of 1,040 articles were identified in the search and seven articles were selected for further evaluation after abstracts and the full text of eligible articles were screened. One economic evaluation used direct patient engagement to account for patient preferences in the final model. The study endpoints identified included a variety of clinical, social, psychological, and economic outcomes. Costs primarily focused on productivity loss, missed work, out-of-pocket treatment costs, and indirect costs to family or friends supporting the patient. Conclusion: To date, the inclusion of the patient voice through patient engagement as part of methods in cost-effectiveness research in existing published studies has been limited. Future CEA studies should consider how patient engagement may impact economic models and their implementation into practice. (Hepatology 2018;67:774-781).